Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 12 of 12 for “"Euphausiids"”.
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Lipid Biomarkers of Bering and Chukchi Sea Euphausiids and Their Application to Diet History
… comprised the dominant lipid class of euphausiids throughout both experiments. Losses were seen in phospholipids, which appear to function in both structural integrity and for energy storage. Major sterols including cholest-5-en-3β-ol (cholesterol), 24-methylcholest-5,22-dien-3β-ol …
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Distribution and population dynamics of Euphausia lucens (Euphausiacea) in the southern Benguela current
… system and then evaluates the contribution of euphausiids to the zooplankton biomass of the southern Benguela region. The study further investigates the population dynamics and maintenance of the dominant euphausiid, Euphausia lucens, principally in the St Helena Bay region because of its …
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Acoustic target classification of zooplankton using machine learning
… kHz) of copepods (Paraeuchaeta norvegica) and euphausiids (Thysanoessa raschii and Meganyctiphanes norvegica) were measured in a tank, and supervised ML classifiers were trained to differentiate them. The best-performing classifiers had a classification accuracy of 96%. However, obtaining …
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Snoek Thyrsites atun in South African waters : aspects of its biology, distribution and fishery
… feeding primarily on anchovy, with pilchard, euphausiids and amphipods also important. Snoek trawled demersally had a more diverse diet, dominated by redeye roundberring, lightfish, lanternfish, hake, buttersnoek and euphausiids. Snoek were caught in the demersal environment throughout …
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Acoustic classification of zooplankton
… (e.g. pteropods), fluid-like (e.g. euphausiids), and gas-bearing (e.g. siphonophores). The relationship between backscattered energy and animal biomass has been shown to vary by a factor of —19,000 across these categories, so that to make accurate estimates of zooplankton biomass …
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The food and feeding of Etrumeus whiteheadi Wongratana 1983, off the Cape Province of South Africa
… mass in the adults. Adult and larval stages of euphausiids were also an important dietary component of these fish, comprising a mean of 10% (range: 0-18%) by mass in the juveniles, a mean of 14% (range: 7-18%) in the transitional juvenile/adult size class and a mean of 52% (range: 27-63%) by …
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Nutritional ecology of Agalma okeni and other siphonophores from the epipelagic western North Atlantic Ocean
… heteropods, veliger larvae, sergestids, mysids, euphausiids, and small fish, though laboratory experiments showed that not all could eat nauplii. Species which could capture Artemia nauplii usually required 2 - 4 hours to digest them, while large prey took 7 - 18 hours to be digested. Since a …
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Examining the feeding ecology of two mesopelagic fishes (Lampanyctodes hectoris & Maurolicus walvisensis) off the west coast of South Africa using stable isotope and stomach content analyses
… far the most important dietary component, with euphausiids contributing 53% of dietary carbon. Conversely, copepods - particularly Calanus sp. - were the most important component of the diet for M. walvisensis in terms of their occurrence (84%), numerical abundance (64%), and dietary carbon …
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Modeling Nutrient and Plankton Processes in the California Coastal Transition Zone
… size fractions, copepods, doliolids, euphausiids and a detritus pool. The wavelength dependent attenuation of the subsurface irradiance field, due to sea water, phytoplankton pigment concentrations and dissolved organic m atter, is incorporated as a depth-dependent energy flux which …
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Examining the trophic ecology of five myctophid genera in the southern Benguela using morphological, stomach content and stable isotope analyses
… an array of macro- and meso-zooplankton with euphausiids being the principal prey item in terms of %IRI for all five genera. Significant differences in average prey length were observed between the genera and the positive sizerelated shift in average prey length noted for Symbolophorus spp. …
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The impact of ocean climate variability on prey availability and the reproductive performance of a planktivorous seabird, ancient murrelet (Synthliboramphus antiquus)
Climate change is an increasing concern to the biological health of marine ecosystems as evidenced by exacerbating change to the natural variability in physical and chemical oceanographic conditions. As upper trophic level predators, colonial seabirds are useful indicators to assess long-term …
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Influence of ecosystem variability on the demography and reproductive performance of two Eudyptes penguins, Macaroni and Eastern Rockhopper Penguins, at sub-Antarctic Marion Island, 1994–2019
… prey species. Both penguins mainly fed on euphausiids Thysanoessa vicina and Euphausia vallentini. Myctophid fishes (mainly Krefftichthys anderssoni and Protomyctophum tenisoni) were more important in the diet of Macaroni than Eastern Rockhopper Penguins. There was no long-term change in …